The dual purposes of the Study Design and Clinical Specimen Core (Core F) are to promote the use of appropriate study design, statistical analyses, and interpretation for clinical and basic science investigators and to assist these investigators in acquiring clinical specimens to facilitate their research. The specific goals of this Core are: (1) to provide epidemiologic and statistical design and analysis support; (2) to establish procedures for data management and to organize databases to permit efficient analyses; and (3) to assist DDC investigators in acquiring clinical specimens needed for their research. Core F will be located in the VA HSR&D Houston Center of Excellence, which is located on the campus of the Houston VA Medical Center. The Center of Excellence, which was established in 1990, is a clinical research facility funded by the Department of Veterans Affairs and is one of 11 such Centers in the nation. Core F thus was developed from and makes use of this outstanding, nationally recognized research faculty. The services provided by the Core include study design (e.g., study population identification, sample size and power estimates), data management (e.g., design development and maintenance of databases) and statistical analyses. These services will be available to both clinical and basic science investigators. This Core also will offer didactic training via Baylor College of Medicine's Clinical Scientist Training Program, which was recently funded via an NIH K-30 Clinical Research Curriculum Award. Finally, the Core has established formal mechanisms and specific procedures to basic science investigators with access to clinical specimens, including the Texas Gulf Coast Digestive Diseases Center Upper and Lower Bowel Specimen Protocol and the Pediatric GI Tissue Bank. It is anticipated that the availability of this Core will greatly increase the use of study design and biostatistical expertise by both clinical and basic scientists, and will markedly enhance the ability of DDC scientists to conduct translational research projects that traverse the gap from bench to bedside.